If you’ve got a new as or electric oven that is in degrees Celsius and used to cooking in degrees Fahrenheit then you are probably needing a temperature calculator to work out the gas mark equivalent.
Or it’s possible the recipe calls for a moderate oven, and you need to know what to heat the oven too. This is a guide only and not exact conversions and different manufacturers and oven types do vary, so always refer to your cooker instruction book.
Fan assisted ovens are usually set approximately 25 degrees Celsius (i.e. approximately 50 degrees Fahrenheit) lower than others and cooking time is reduced by 10 minutes for every hour of cooking time.
The heat of an oven is important to cooking to the centre of meat.
| Degrees Fahrenheit | Degrees Celsius | Gas Mark | Description |
| 225 | 110 | 1/4 | Very slow |
| 250 | 120/130 | 1/2 | Very slow |
| 275 | 140 | 1 | Slow |
| 300 | 150 | 2 | Slow |
| 325 | 160/170 | 3 | Moderate |
| 350 | 180 | 4 | Moderate |
| 375 | 190 | 5 | Moderately hot |
| 400 | 200 | 6 | Moderately hot |
| 425 | 220 | 7 | Hot |
| 450 | 230 | 8 | Hot |
| 475 | 240 | 9 | Very hot |
How to Convert Fahrenheit to Celsius
As a rule of thumb Celsius is roughly half the Fahrenheit temperature, but the equation to convert degrees Fahrenheit to degrees Celsius, you subtract 32 to the Fahrenheit temperature, multiply by 5, then divide by 9.
For example, to convert 400 degrees Fahrenheit to Celsius you would:
- 400 degrees Fahrenheit – 32 = 368
- 368 x 5 = 1840
- 1840 / 9 = 204.44
This is commonly rounded down to 200°C
How to Convert Celsius to Fahrenheit
To convert degrees Celsius to degrees Fahrenheit, it’s the same equation in reverse. So you multiply degrees Celsius by 9, divide by 5, then add 32.
For example, to convert 200 degrees Celsius to Fahrenheit you would:
- 200 x 9 = 1800
- 1800 / 5 = 360
- 360 +32 = 392℉
Why is the cooking temperature important?
It’s essential to cook food at the right temperature and for the correct length of time to kill any harmful bacteria. This is especially true for meat which has to cook all the way through so juices run clear.
You should always check the advice and cooking instructions on food packaging and check the meat is cooked correctly as it may need longer if the oven is full. This is why meat thermometers are popular and now inbuilt in high end modern ovens.
Beef can be served rare, as the bacteria is on the outside surface of the meat. But when minced for making a burger or meatballs this can be spread inside the burger.
How do Ovens cook?
This is done through a combination of three different heat transfer methods.
Convection (Fan Ovens)
This is standard for most eclectic ovens where the air is heated and travels over and through the food. It is why fan assisted ovens cook faster.
Radiant or direct heat
When the flames at the back of a gas oven or the element in an electric oven cook the food.
Conduction
This is where the heat travels through the shelf, into the baking tray/dish and then on into the food.
